The described invention related generally to systems for machining materials and more specifically to a system for machining materials into which an ultrasonic machining module has been incorporated, wherein the ultrasonic machining module is compatible with a variety of machining processes.
Machining, which is a collective term for drilling, milling, reaming, tapping, and turning, is an enabling technology that impacts virtually all aspects of manufacturing in the United States and elsewhere. With regard to a specific example, a milling machine is a machining tool used to machine solid materials. Milling machines are typically classified as either horizontal or vertical, which refers to the orientation of the main spindle. Both types range in size from small, bench-mounted devices to much larger machines suitable for industrial purposes. Unlike a drill press, which holds the workpiece stationary as the drill moves axially to penetrate the material, milling machines move the workpiece axially and radially against the rotating milling cutter, which cuts on its sides as well as its tip. Milling machines are used to perform a vast number of operations, from simple tasks (e.g., slot and keyway cutting, planing, drilling) to complex tasks (e.g., contouring, diesinking).
The accessories and cutting tools used on machine tools (including milling machines) are referred to in aggregate as “tooling”. Milling machines often use CAT or HSK tooling. CAT tooling, sometimes called V-Flange Tooling, is the oldest and probably most common type used in the United States. CAT tooling was invented by Caterpillar Inc. of Peoria, Ill., to standardize the tooling used on Caterpillar machinery. HSK tooling, sometimes called “Hollow Shank Tooling”, is much more common in Europe where it was invented than it is in the United States. The holding mechanism for HSK tooling is placed within the hollow body of the tool and, as spindle speed increases, it expands, gripping the tool more tightly with increasing spindle speed.
Improving the machinability of certain materials is of significant interest to manufacturers of military equipment and commercial hardware, as well as to machine tool builders. More specifically, very advanced materials such as armor plates and composites are notoriously difficult to machine with standard methods. High-speed systems and ultra-hard tool bits are used for materials such as these, but provide only a marginal increase in tool life and productivity. Significant improvements in the machinability of materials have been achieved by implementing advanced technologies such as laser, waterjet, and EDM cutting. However, these processes are high in capital cost, limited in application, and differ too much to be used in standard machine shops. Also, their application is limited to certain types of cuts in materials.
Ultrasonic-assisted machining was developed in the United States in the 1950's and was used for machining materials that were considered to be difficult to machine at the time. The more modern process of ultrasonic machining (UM) involves the application of high power ultrasonic vibrations to “traditional” machining processes (e.g., drilling, turning, milling) for improving overall performance in terms of faster drilling, effective drilling of hard materials, increased tool life, and increased accuracy. This is typically accomplished by using high speed steel (HSS) drill bits affixed to a shrink fit collet that is bolted to an ultrasonic (US) transmission line. In this context, UM is not the existing ultrasonic-based slurry drilling process (i.e., impact machining) used for cutting extremely hard materials such as glass, ceramics, quartz. Rather, this type of UM concerns methods for applying high power ultrasonics to drills, mills, reamers, taps, turning tools, and other tools that are used with modern machining systems.
Although the use of ultrasonics with modern machining systems provides significant and numerous benefits, there are certain technical challenges involved, not the least of which is the incorporation of ultrasonic energy into machining systems that were not originally designed to accommodate this type of energy output. Thus, there is an ongoing need for an ultrasonic machining module that is compatible with and that may be incorporated into existing machining systems.